kidspot:If I were to bring up the PO Halo effect found in what is called "original rock" which could only have formed had that granite cooled instantaneously, they would show their studies that conclude otherwise.
Aloha, Tim
Hi there Tim - I'm just tuning into this debate again after a spell: could you elaborate on what you mean by the above - the thermodynamics and cooling path of a granite body (or any other igneous rock) is a very easy thing to model and indeed is being measured as we speak. We're talking cubic kilometres of SiO2-Al-K-Na goo crystallising into a few well known mineral species over a limited number of pressure/temp/composition paths to form most igneous plutons.
You simply can not extract heat fast enough in the hot insulating lower crust (>300C) where granite bodies settle to solidify them inside a few million years: and radiometric age dating of progressive crystallisation of hundreds if not thousands of older igneous bodies supports the thermodynamic models.
This is of course unless god made it that way, in which case we are dealing with a god with a sense of humour who likes practical jokes...
This will be at at 2000 posts soon..
Cheers,
Rohan.